去年在同一十字路口发生过类似的事故。

A similar accident ___occurred at the same intersection last year.

如果机器没有得到适当维护，可能会发生严重损坏。

Serious damage can ___occur if the machine is not properly maintained.

现场直播期间有时会出现技术问题。

Technical problems sometimes ___occur during the live broadcast.